Venetian blind



Feb. 16, 1954' C. S. EVANS VENETIAN BLIND Filed Oct. 14, 1946 INVENTORbody which flattens into a strong,

tion, showing on an enlarged scale that portion of Figure 1 which isenclosed by the dotted circle 5.

Figure 6 is a vertical sectional view through the bottom rail and lowerslat. The plane of section is indicated by the line 6-6 of Figure 1.Figure '7 is a plan view, and Figure 8 is an elevation partly invertical section of a fastening element slidably supported on the twincross tapes. Figure 8 is on an enlarged scale; and in all of the figuressmall or thin parts are necessarily shown somewhat out of scale.

A Venetian blind generally includes a series of thin horizontal slats,with mechanism for adjusting their vertical position to vary the amountof window opening covered; and mechanism for tilting the slats withreference to the horizontal plane in order to vary the degree of openingof the blind; at all times the slats being maintained in parallelism. Myinvention is not primarily concerned with either the lifting cord lockor the tilting mechanism; excellent devices for those purposes havinglong been available. These por tions of the blind embodied in myinvention will therefore be referred to, but not explained in detail.

My blind comprises a ceiling board 2 having a tilting head 3 of commonworm gear type at one end, and a bracket 4 at the other end forming partof the cord lock 5. between the tilting head 3 and the bracket; andcords 8 hanging down on the left side of the blind, provide means forturning the tilt rail. A molding 9 secured to the ceiling board extendsacross the front of the structure and conceals the tilt rail,

' tilting head and cord lock.

Detachably secured to the tilt rail near each end is a ladder tape inwhich the slats it are hung and demountably secured. Each ladder tapecomprises front and rear vertical webs l2 and I3 respectively, extendingdownwardly from the tilt rail to the bottom rail it. A detachablefastening means i'l, preferably of snap fastener type, secures the endof each web to the bottom rail.

By snap fastener, I mean two-part releasable connecting device,comprising an annularly grooved stud which is fixed on one of the partsto be connected, and a resilient ring into which the stud may beinserted to be resiliently held thereby, and which is fixed on the otherpart.

The upper ends of the ladder tape webs are releasably connected by snapfasteners 18 to op posite ends of the saddle 19, fixed by double pointedtacks 2! to the top surface of the tilting rail; and hanging free overthe curved sides of the rail as shown in Figure 1. The saddle may bemade of thin leather or of light canvas stitched about the edges toprevent raveling. When laid out flat the saddle has the shape of anelongated ring. The center opening provides a free space surrounding thegroove 22 in the side of the tilt rail, through which the lifting cord23 passes.

The proportion and arrangement of parts are such that when the tilt railis horizontal the bottom rail is also horizontal. Extending between thevertical webs l2 and 13 of each ladder tape are the rung tapes or crosstapes on which the slats 9 lie; and these are evenly spaced lengthwiseof the webs so that the slats lying thereon will maintain parallelismwith each other and with the tilt and bottom rails.

The rung tapes are arranged in pairs 25 and 2t; and preferably areformed of a braided tubular double-thick- A tilt rail 1 is supported 4ness, rather narrow cord-like tape. The ends are woven or sewed to theweb; and at midpoint between the webs, the ring member 21 of a snapfastener is secured to both; the two parts of the ring clamping thetapes securely between them. Preferably the points of securement of thetwin tapes to the webs and the fastener ring are such as to space theirouter ends somewhat further apart than their midpoints caught in thefastener ring, as shown in Figure 2. There are several reasons for this:a more even and balanced stress is placed on the webs; there is lesstendency for the fastener ring to tip out of the horizontal, easilyengageable position when free of the slat; there is less tendency of theslats to sway lengthwise so that the blind has a greater verticalstability; and a freeway for the lifting cord with no frictionalengagement against the tapes is ensured.

Lying on the corresponding sets of twin tapes in each ladder are theslats it, each of which carries a stud member 28, so placed that whensnapped into its associate ring 21, the slat is aligned laterally withother slats and with the bottom rail. It is to be noted that the slat isdemountably secured directly to the twin supporting tapes, and throughthem to the vertical webs of the ladder. The eye demands alignment ofthe slats with the ladder webs which are the dominant vertical elementin the design formed by the blind as a whole. The twin cross tapes areheld taut by the weight of the slat; and since the slat is fastened tothe twin tapes, accurate alignment is assured.

While a snap ring may join the centers of each set of twin tapes, asshown in Figure 2, and associate studs placed on each slat, it ispreferred for reasons involving costs of manufacture and ease with whichthe slats may be detached and taken out, to use but one snap fastener toa slat; and to stagger these in the two ladders, so that as to eachladder, alternate slats are fastened to the twin tapes, the other end ofthe fastened slat being unsecured to the twin tapes on which it lies.

It will be noted that bringing the center portions of the twin tapescloser together in the snap ring, than the ends fixed to the verticalwebs, tends to shorten the distance between the latter, so that whenfasteners are applied to every other set of twin tapes, the interveningsets are, in effect, somewhat longer since they extend straight acrossbetween the webs. This small variation when it occurs may be readilyeliminated if desired during manufacture of the ladder tape, but thevariation is so slight as to be negligible. Furthermore any variation issymmetrical and balanced from the side to side and for that reason isunnoticeable.

Means are provided for lifting the bottom rail so that as it rises, theslats are successively stacked thereon, until all are collected at thetop of the blind between it and the tilt rail. On its upper face theceiling board is formed with grooves in which lie the two strands of acord loop 32. One strand 23 passes over a pulley 34 and down through theunderlying saddle l9 and groove 22 in the side of the tilt rail, thendown between the rear edge of the slats and the rear web l3, and throughthe spaces between the ends of the twin tapes supporting each slat, tothe bottom rail where the end passes through a groove 36 and terminatesin a knot seated in a recess 31 formed to one side of the center in thebottom of the rail where it is covered by the bottom end of the web.

The other strand 38 passes over pulley 39, and extends down similarlybut in front of the slats and next to the front web I2. The two liftingcords 23 and 38, secured on opposite sides of the bottom rail aresufiioient, but with a particularly long or heavy blind, a lifting cordmay be arranged on each side next the front and rear webs in each laddertape.

As the blind is pulled up from its lower position to stack the slats onthe lower rail, the lifting cord moves smoothly upwardly with no lateralcontact with the twin cross tapes since it lies midway between them; andwith but light engagement with slat and web. With long and heavy blinds,it may be desirable to relieve the slat a small amount along the edgeadjacent the lifting cord, as shown at 42, Figure 3, so that the cordmoves past the slat with substantially no rubbing of the edge. Becauseeach lifting cord, from bottom rail to top pulley, is almost free offrictional drag, except for a slight amount from the web which decreasesas the blind is raised, my blind is noticeably easy to operate. Becauseof the balanced distribution of stresses on the webs, which results fromthe twin rung tapes, there is no tendency to uneven folding of the webs,which gather into vertically aligned and even folds as the blind rises.This result is materially aided by the securement of the slats to therung tapes since that construction tends to prevent relative lateralmovement of either one while promoting vertical alignment of the slatsas the stack forms.

From the foregoing explanation it will be clear that the slats arereadily demountable; and that any one or all of them may be detachedfrom the rung tapes by separation of the fastener elements, and thenremoved from the blind for cleansing or other treatment, after whichthey may be reinserted and snapped in place. If it is desired to cleanor replace the ladder tapes, the slats are first unsnapped and removed.The lower snaps I! are then opened to free the lower rail from the endsat the bottom of each ladder web, and disengage the knotted ends of thelifting cords from the recesses in the bottom face of the rail. The railmay then be removed. By disengaging the snaps l8 on both sides of thesaddle, the ladder tape may be pulled free, leaving the lifting cordshanging loose from the tilt rail, ready for reassembly of ladder tape,bottom rail and slats.

In Figures 7 and 8, I have shown a modificae tion of the rung tape andfastener structure. It is desirable in some cases to space the twin rungtapes further apart than can be caught by a rather small standardfastener element. Sometimes also it is an advantage to permit a smallamount of shifting of the slat along the rung tapes toward one of thewebs. Either or both of these conditions may be satisfied by setting thetwo elements 48 and -41 of the fastener ring on opposite sides of a thinplate 48 having an aperture 49 therethrough in which the fastener iscentered. The fastener thus is mounted directly on the plate instead ofdirectly on the twin tapes as in Figure 2. It will be obvious thatinstead of inserting a, thin apertured plate between the fastenerelements, the lower element itself may be extended on opposite sides toprovide the desired plate. In either case, the opposite ends of theplate are bent over and under as shown, to provide broad open resilienteyes 5| adapted to be hooked over the twin rung tapes 52, as shown inFigure 8.

The opening of the eye should be sufficient to permit entrance of thetape under light stress and free movement of the plate along the tape,if such movement is desired. If the plate is to be fixed on the crosstapes, the eye is smaller so as to clamp the tape therein.

I claim:

1. A ladder tape for a Venetian blind comprising spaced webs, twin rungtapes spaced apart and connected at their ends to the webs, and afastener element bridged across the twin tapes intermediate their ends,the distance between the twin tapes at the fastener element being lessthan between their ends.

2. A ladder tape for a Venetian blind comprising spaced webs, twin rungtapes spaced apart and connected at their ends to the webs, a platebridged across the twin tapes intermediate their ends and spacing thetapes closer together than at their ends, and means adjacent oppositeedges of the plate to fix the plate to the rung tapes.

3. A ladder tape for a Venetian blind comprising spaced webs, twin rungtapes spaced apart and connected at their ends to the webs, a platebridged across the twin tapes intermediate their ends and spacing thetapes closer together than at their ends, and opposing surfaces adjacentopposite edges of the plate to fix the plate to the rung tapes.

CHARLES S. EVANS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 451,924 Fisher May 12, 1891 1,861,606 Mackin June 7, 19322,031,981 Runge Feb. 25, 1936 2,043,501 Wood June 9, 1936 2,111,978Lawson et a1 Mar. 22, 1938 2,123,817 Warren July 12, 1938 2,141,502Ajouelo Dec. 27, 1938 2,200,349 Walker May 14, 1940 2,311,716 WalkerFeb. 23, 1943 2,317,660 Williams Apr. 27, 1943 2,381,060 Kahn Aug. 7,1945

